Blast furnace monkey



NOV. 1953 J. B. CASEY ET AL BLAST FURNACE MONKEY Filed March 28. 195] l I I I I I I I I I i 1 a f (Ilia a82 INVENTORS,

ATTORNEYS Patented Nov. 3, 1953 UN I TED STATES PAT EN T "OFFICE BLAST FURNACE MONKEY B. Ga'sey and Grady A. Smitherman, Wood'- wa'rd, Ala., assig'nors -to Woodward Iron Comzpany, Woodward, a corporation ApIiIica tionMarch ZB, 1951, SerialNoeZ'ifi-Oillt .Our invention, in its broadest "aspect, relates to a new and useful improvement in the method of drawing slag from a blast furnace, accomplished by a change in the construction of the blast furnace monkey.

In the operation of a blast furnace producing pig iron or other metals from metal ore it is, from time to time, necessary to draw from the furnace hot slag by means of removing the plug or bott in the center of "the 'monkeyinstalledin the furnace, thus allowing the slag to be drawn through the monkey.

The conventional type monkey is a casting inserted in the furnace, which casting is cooled by an annular water space within the monkey and having an opening through the center of the monkey which is closed by a plug or bott. Experience has shown that with the conventional monkey the action of inserting and withdrawing the plug or bott (for the purpose of drawing off slag) coupled with the intense heat from the flowing slag, acted to enlarge the original opening in the monkey by a combination of abrasion and shaping of the metal sides of the opening due to intense heat. As a result of this action the opening in the monkey would gradually be enlarged so that the wall thickness between the opening in the monkey and the annular water space within the monkeywould be reduced until it was ruptured, thus allowing water to leak out of the monkey and into the slag. The rupturing of the wall into the water space with the conventional type monkey occurs every three to four days, necessitating shutting the furnace down while the ruptured monkey is replaced with a new one.

The broad object of our invention is to so construct the monkey through which the hot slag is drawn from the blast furnace that the useful life of the monkey will be greatly increased, thereby reducing substantially the amount of time the blast furnace is out of operation while a new monkey is installed.

A more specific object of the present invention is to form on the wall of the conventional tapered bore of a blast furnace monkey, at the large end thereof, an annular, constant diameter rib or boss receiving the conventional tapered plug or butt, and so formed relative to the formation of the bott as to prevent the boss from wearing off for a substantial period of time.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of 2 after-more fully describedand pointed out in the claim, it being understood that-changes maybe made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings,

1 is a top plan view' of a blast furnace monkey formed in accordance with the present invention.

Fig. 2 is a front elevation.

Fig. 3 is a sect'ion 'on line 3-3 "of Fig. 2, an "inserted plug "or bott being illustrated in chain dotted -line's.

Referring to the "drawings in detail, the monkey is formed with an inner wall generally designated I an-d having a bore 2 opening at opposite :ends or the monkey. The bore :2 is of tapered formation as readily seen from Fig. 3, the large end of the :bore being disposed at the front end of the monkey.

An outer jacket or wall 3 surrounds and is spaced from the inner jacket or wall to define therebetween an annular Water space within the monkey and surrounding the bore. The water space is closed at opposite ends by a front wall '4 and rear wall 5. A partition -6 is provided in the water space, extending from front to rear of the monkey, and is integral with .the inner and outer walls I and 3. I-nlet and outlet openings 1 and 8 are formed in the .front Wall at opposite sides of said partition, whereby water circulated through the water space. Openings 1 and 8 are threaded inthe customary manner.

The construction so far described is thoroughly conventional in a blast furnace monkey and does not per se constitute part of the present invention.

In accordance with the present invention, we form on the surface of the bore 2, at the large end of the bore, an annular rib or boss 9, defining a circular cylindrical surface. As may be noted by reference to Fig. 3, the thickness added to the inner wall I provides a surface of a width which exceeds the thickness of the walls of said body. In a practical embodiment of the invention, the inner wall I is of the standard thickness of three eighths inch, while the thickness of the annular boss is one eighth inch, at the inner end of the boss seen as the right hand end in Fig. 3.

In blast furnace monkeys of conventional construction, rupturing of the inner wall I takes place approximately at a location designated 10.

In this connection, over a period of one year,

construction and combinations of parts, hereinstatistics maintainedonthree representative blast 3 furnaces in which conventional monkeys were used, are of interest and showed the following:

Average Life Monkeys Per Monkey Furnace Used 3.52 days. 3.25 days. 4.30 days.

Average Life Monkeys Per Monkey FIII'DBCB Used It may be noted, in connection with the results stated for #3 furnace, that the figures given are not wholly representative of the service given through the use of monkeys formed in accordance with the present invention, since the furnace was out of blast four days, and in starting up the furnace once again, the operations were such that extra monkeys had to be used.

During the three months test period, the maximum life on one monkey was 39 days. The figures set forth above are of particular interest when it is observed that the plant average number of days of life per monkey was more than three times greater than it was when conventionally designed monkeys were used, and this despite the fact that the annular boss increases the thickness of the inner wall by only a small fraction of its previous thickness. In other words, whereas it took an average of 4.06 days for the inner wall to wear through to the point 0 in the conventional monkey, said inner wall being of a three eights inch thickness, it took 13.5 days to wear through, to the point It), an annular boss one eighth inch thick and an inner wall three eighths inch thick.

While we cannot state with certainty the exact reasons for this greatly added wear capacity, we believe that it may be due in part to the use of a constant diameter boss receiving a tapered plug or bott T, and in part to the particular location of the boss, that causes the wear to proceed along a difierent, substantially longer path than was previously the case.

Considering this further, it may be noted that the front edge of the annular boss is disposed substantially forwardly of the point III at which rupture takes place eventually, and a line drawn between said front edge of the boss, seen as the left hand edge in Fig. 3, to said rupture point is substantially longer than a line dropped straight downwardly from said rupture point to the surface of a tapered bore used in the conventional monkey. Since the boss is of constant diameter, while the plug or bott is tapered, original insertion of the plug to wedge it into the boss causes the plug to contact the boss only at the front edge thereof. As a result, as wear proceeds, continued reinsertion of the plug wears away first the front edge portion of the boss, and then successive, more rearwardly disposed portions, until the boss is fully worn away, after which wearing away of the inner wall 4 begins.

What is claimed is:

A blast furnace monkey comprising a hollow body having elongated spaced concentric walls of conical form, end walls carried by and extending between the concentric walls to define a chamber through which a cooling liquid may be circulated, the innermost concentric wall defining a passage which extends through the body and which diminishes in diameter as it recedes from one end of the body, a partition carried by the concentric walls and extending radially therebetween, the end wall at the larger end of the body having a liquid inlet opening extending therethrough and opening into the chamber adjacent one side of the partition and a liquid outlet opening extending therethrough and opening into the chamber adjacent the opposite side of the partition, an annular inwardly extending flange integral with the body and extending into the passage adjacent the larger end thereof, and the inner edge of the flange defining a circular cylindrical surface having a width which slightly exceeds the thickness of the walls of the body and against which a plug is adapted to seat when the passage is closed.

J. B. CASEY. GRADY A. SMITHERMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,536,755 Berg Mar. 5, 1925 2,409,337 Yuhas Oct. 15, 1946 FOREIGN PATENTS Number Country Date 627,894 Germany Mar. 25, 1936 

